/* ** AIFF_CD.h - header file defining both chunks of the AIFF-CD standard in C ** and the standard itself ** ** $Id: AIFF_CD.h 1.6 1998/11/02 11:52:47 patrick Rel patrick $ ** ** $Log: AIFF_CD.h $ ** Revision 1.6 1998/11/02 11:52:47 patrick ** added the authors mail address ** ** Revision 1.5 1998/11/02 11:46:02 patrick ** External filenames are explicitely required to follow the Amiga convations. ** Added explanation of this convention. ** ** Revision 1.4 1998/07/02 11:45:56 patrick ** added RCS logging ** ** ** Revision 1.3: ** added example ** Revision 1.2: ** added macros to step between ACD_TRInfos ** Revision 1.1: ** initial revision ** ** ©1998 Patrick Ohly, Patrick.Ohly@gmx.de */ #ifndef AIFF_CD_H #define AIFF_CD_H /* ** CD-ROM extensions to AIFF[-C] standard ** ====================================== ** ** 1. Introduction ** --------------- ** ** The intention of this document is to define an extension to the AIFF and ** AIFC data file format that allows such files to represent all informations ** relevant to an audio and mixed-mode CD (data track + audio tracks). ** ** Knowledge about these two standards and IFF are expected. This document uses ** the same data type notation as in those standards. AIFF is used as a synonym ** for both AIFF and AIFC from now on. ** ** This documents's main focus are definitely audio CDs. It does not try to ** represent all possible types of CDs, only those that consist of one session, ** consecutive audio tracks plus one optional data track at the beginning. ** ".aiff-cd" and ".aifc-cd" should be used as suffices for this new file ** format. ** ** The audio tracks are stored in the usual AIFF way and can have any format ** valid for AIFF. It is up to applications to cope with different number of ** channels, bits per sample, and frequency correctly. ** ** This approach has the advantage that existing audio applications can access ** the audio data without any modifications in the program. It has the ** disadvantage that the audio data has to be copied, too. ** ** Therefore the audio data for each track may alternatively be stored in ** another file that is only referenced by the AIFF-CD file. The contents of ** this other file is not defined by this standard. ** ** Applications aware of the CD-ROM extensions may store the following ** informations: ** - International Standard Recording Code (ISRC) and other ** advanced information for some or all tracks ** - Medium Catalog Number for the CD ** - Index markers within each track ** - one data track ** ** These extensions are stored in local chunks within the AIFF ** form. They are defined in the following chapter. They are illustrated ** by an example at the end of this document. ** ** 2. Chunk Definitions ** -------------------- ** ** All of these chunks are optional. It is up to an application to use ** reasonable default values, if necessary. The following data types ** are used in this standard: */ typedef unsigned long ACD_Block; /* logical CD block, 1min = 60s, 1s = 75 blocks, block #0 == 00:02:00 min:sec:frame */ typedef unsigned long ACD_AudioBlock; /* as above, but now relative to beginning of the audio sample: block #0 == 0.0 sec of audio sample */ typedef unsigned long ACD_SampleNum; /* position within an audio sample or amount of audio data; this value is independent from the number of channels, i.e. multiple samples played in parallel only count as one sample */ typedef unsigned long ACD_ULONG; /* 32 bit integer, unsigned */ typedef signed long ACD_LONG; /* 32 bit integer, signed */ typedef ACD_ULONG ACD_ID; /* ** Some more types as defined in the AIFF standard are used in the ** definition of chunks. Any definition not allowed in C (variable sized ** arrays, pstrings, ... ) are excluded using ** #ifdef ACD_NON_C_DATATYPES ** ... ** #endif. ** Take care to handle those entries in the chunks correctly in your code. ** ** These are chunks required for AIFF and AIFC. They are included for ** your convenience only and are explained in the corresponding standards. */ typedef struct { unsigned short exponent; /* Exponent, bit #15 is sign bit for mantissa */ unsigned long mantissa[2]; /* 64 bit mantissa */ } extended; typedef struct { SHORT numChannels; ULONG numSampleFrames; SHORT sampleSize; extended sampleRate; } AIFF_CommonChunk; typedef struct { SHORT numChannels; ULONG numSampleFrames; SHORT sampleSize; extended sampleRate; ULONG compression_ID; } AIFC_CommonChunk; typedef struct { ULONG offset; ULONG blocksize; } AIF_SoundData; /* ** 2.1 Track Information ** ^^^^^^^^^^^^^^^^^^^^^ ** ** For each track its source and type can be defined independently. The data can either ** be contained in the SSND chunk of the AIFF-CD file itself or in the file refered to ** in the track entry. If an external file is used then it is up to the application to ** recognize the format. In both cases the relevant data may be some subpart of the ** source defined by start and length. */ #define ACD_TRI_PREAMPHASIZE (1<<0) /* audio data was sampled with preamphasize */ #define ACD_TRI_COPYRIGHTED (1<<1) /* data has a copyright */ #define ACD_TRI_EXTERNAL (1<<2) /* data is stored in an external file */ #define ACD_TRI_PAUSE (1<<3) /* last entry in index list marks a pause */ typedef struct { ACD_ULONG pause; /* This number of empty blocks shall be generated before the track when writing to CD-R; usually 0. This data will be part of the pregap. */ ACD_SampleNum start; /* beginning and */ ACD_SampleNum length; /* length of the audio data taken from the source(s) */ ACD_ULONG flags; /* ACD_TRI_#? as defined above */ ACD_ULONG numIndices; /* Indices are given relative to the beginning of the real audio data of this track (i.e. 'start'). Index #1 always starts at 0 and has to be omitted. The last entry is the beginning of the index pause if ACD_TRI_PAUSE is set, otherwise just another index. */ /* Entry may be extended in the future by a variable number of bytes; this is the number of bytes appended to this structure at the end in reserved[]. */ ACD_ULONG numReservedBytes; /* 0 at the moment */ #ifdef ACD_NON_C_DATATYPES ACD_AudioBlock indices[]; /* only used with ACD_TRI_EXTERNAL, but always present; filename can be absolute or relativ to the directory the AIFF-CD file is stored in. AIFF-CD follows the Amiga filename conventions: [[»volume«]:][[»dir«]/]*»filename« »volume«, »dir« and »filename« are 8 bit characters without colon (":") and slash ("/"). Absolute paths are specified with the optional volume name followed by a colon. The colon alone refers to the root directory of the filesystem that contains the AIFF-CD file. The usage of the absolute part of the filename on non-Amiga systems is not specified. The path specification is similar to Unix, with only one exception: a slash without a preceeding directory name refers to the parent directory. E.g. "dir1/dir2//file" = "dir1/file" "/" = parent directory of current directory */ pstring externalFile[]; byte reserved[]; /* just skip these bytes if the contents is unknown */ #endif } ACD_TRInfo; /* ** Going from one ACD_TRInfo to the next is a bit tricky because of the ** variable sized entries at the end. These macros can be used in C to get ** pointers to the first ACD_TRInfo, all following ones and indices[]/ ** externalFile[]/reserved[]. ** ** ACD_FIRST_TRINFO() expects a pointer to the ACD_TRInfoChunk structures ** as defined below, including all the data of the chunk. The chunk header ** has to be part of this data if and only if ACD_CHUNK_HEADER was defined ** to include it in the C structure, too. ** ** The same applies to the other macros which expect a pointer to ** ACD_TRInfo. */ #define ACD_FIRST_TRINFO(tr_infos) \ ((ACD_TRInfo *) &((ACD_TRInfoChunk *)tr_infos)[1]) /* skip general infos */ #define ACD_TRINFO_INDICES(tr_info) \ ((ULONG *) &((ACD_TRInfo *)tr_info)[1]) /* skip track specific infos of constant length */ #define ACD_TRINFO_EXTERNAL(tr_info) \ ((UBYTE *) &ACD_TRINFO_INDICES(tr_info)[((ACD_TRInfo *)tr_info)->numIndices]) /* start at indices and skip all of them */ #define ACD_TRINFO_NEXT(tr_info) \ ((ACD_TRInfo *) &ACD_TRINFO_EXTERNAL(tr_info)[ACD_TRINFO_EXTERNAL(tr_info)[0] + \ ((ACD_TRINFO_EXTERNAL(tr_info)[0] % 2) ? 1 : 2) + \ ((ACD_TRInfo *)tr_info)->numReservedBytes]) /* start at external file name, skip the name itself, the length byte and the optional pad byte and finally the reserved bytes */ /* ** The different TRInfos are gathered in one obligatory chunk: */ #define ACD_TRINFOID 'TRIF' typedef struct { #ifdef ACD_CHUNK_HEADER ACD_ID ckID; /* 'TRIF' */ ACD_LONG ckDataSize; #endif ULONG version; /* 1 at the moment - don't accept versions you don't know, any other chunk might have changed */ ACD_ULONG firstTrackNum; /* the first track number can be chosen, the following once increase in steps of one */ ACD_ULONG numTRInfos; #ifdef ACD_NON_C_DATATYPES TRInfo TRInfos[]; #endif } ACD_TRInfoChunk; /* ** 2.2 ISRC ** ^^^^^^^^ ** ** For each track at most one ISRC can be specified. Tracks are referenced by ** their index in the track info array, not by what they would have on CD. ** Only some characters are allowed for the four components of an ISRC. Each ** component has to consist of exactly the right number of characters. */ typedef char ACD_AZASCII; /* ASCII value of characters A-Z */ typedef char ACD_AZ09ASCII; /* ASCII value of characters 0-9 and A-Z */ typedef char ACD_09ASCII; /* ASCII value of characters 0-9 */ typedef struct { ACD_ULONG track; /* the same as in the CDMarkers */ ACD_AZASCII country[2]; /* country code */ ACD_AZ09ASCII owner[3]; /* owner code */ ACD_09ASCII year[2]; /* year of recording */ ACD_09ASCII serial[5]; /* serial number assigned by owner */ } ACD_ISRC; /* ** The different ISRCs are gathered in one optional chunk. ** Not every track must have an ISRC, but entries have to be ** sorted on the track number in increasing order. */ #define ACD_ISRCID 'ISRC' typedef struct { #ifdef ACD_CHUNK_HEADER ACD_ID ckID; /* 'ISRC' */ ACD_LONG ckDataSize; #endif ACD_ULONG numISRCs; #ifdef ACD_NON_C_DATATYPES ISRC ISRCs[]; #endif } ACD_ISRCChunk; /* ** 2.3 Medium Catalog Number ** ^^^^^^^^^^^^^^^^^^^^^^^^^ ** ** This optional chunk stores the UPC/EAN number of the CD. The same rules ** for valid characters and length as for ISRC apply. */ #define ACD_MCNID 'MCNU' typedef struct { #ifdef ACD_CHUNK_HEADER ACD_ID ckID; /* 'MCNU' */ ACD_LONG ckDataSize; #endif ACD_09ASCII MCNum[13]; /* Medium Catalog Number */ ACD_09ASCII pad; } ACD_MCNChunk; /* ** 2.4 Data Track ** ^^^^^^^^^^^^^^ ** ** This optional chunk is not relevant for audio applications. It is used ** by CD writer software to allow the user to store the image of a ** complete CD in one file. An audio application should copy this chunk ** unchanged when writing back a AIFF-CD file or warn the user if it is ** not able to do so. ** ** Different types of data can be stored and different data formats are ** allowed. More types may be defined latter. An applications should be ** prepared to issue a meaningful warning (perhaps using the data type and ** format names specified in the chunk) if unknown or unsupported data is ** found. */ typedef enum { ACD_MODE1, /* CD-ROM mode 1 (block size 2048 bytes) */ ACD_MODE2, /* CD-ROM mode 2 (2336 bytes) */ ACD_MODE2_FORM1, /* XA mode 2, form 1 (2048 bytes) */ ACD_MODE2_FORM2 /* XA mode 2, form 2 (2324 bytes) */ } ACD_DataType; typedef enum { ACD_DF_COOKED, /* only user data with block size as specified above */ ACD_DF_RAW /* complete block of 2352 bytes, containing user data, sync, (sub) header and EDC/EDD as specified in the MMC standard; not scrambled */ } ACD_DataFormat; /* ** These enumerations have the following English names: */ #ifdef ACD_NAMES char *ACD_TypeNames[] = { "Mode 1", "Mode 2", "Mode 2, Form 1", "Mode 2, Form 2" }; char *ACD_FormatNames[] = { "cooked", "raw" }; #endif /* ** The data track contains data with the block size specified by type and ** format. This data is placed in a chunk on its own to allow seperate ** writing of the data and the control information. The number of blocks ** is deduced from the length of this chunk and the block size. ** ** The track starts on the CD at a specific logical CD ** block ("startBlock") and must not be relocated without appropriate warnings or ** transformations. The data may contain some blocks ("preGapLen") that are ** already part of the pregap between the data track and the following audio ** track. This pregap is described by the logical CD block number where the ** the second, audio part starts ("audioPregapStart") and the logical CD block ** number where the audio data is placed ("audioStart"): ** ** # trackType/Format data in the data chunk ** + " " " that has to be generated ** * audio data as defined by the track infos chunk ** (a pause requested for the first audio track is valid and ** moves the audioStart) ** - audio data that has to be generated ** ** #####################################+++------------------**************** ** | | | | | ** startBlock <- preGapLen -> audioPregapStart audioStart ** <--- data track ---> <--- pregap (index 0) ---> <-- audio track ** ** All these values are placed in this chunk: */ #define ACD_DATATRACKINFOID 'CDTI' typedef struct { #ifdef ACD_CHUNK_HEADER ACD_ID ckID; /* 'CDTI' */ ACD_LONG ckDataSize; #endif ACD_DataType trackType; ACD_DataFormat trackFormat; ACD_Block startBlock; /* usually #0 */ ACD_ULONG preGapLen; ACD_Block audioPregapStart; /* >= startBlock + number of blocks */ ACD_Block audioStart; /* > audioPregapStart */ ACD_ULONG flags; /* none defined at the moment */ ACD_ULONG reserved[4]; /* has to be set to 0 */ #ifdef ACD_NON_C_DATATYPES pstring trackTypeName; /* from TypeNames */ pstring dataFormatName; /* from FormatNames */ #endif } ACD_DataTrackInfoChunk; /* ** This is the chunk for the track data itself. It has to be present if ** the data track is present. */ #define ACD_DATATRACKDATAID 'CDDT' #ifdef ACD_NON_C_DATATYPES typedef struct { #ifdef ACD_CHUNK_HEADER ACD_ID ckID; /* 'CDDT' */ ACD_LONG ckDataSize; #endif /* pure data - number of blocks can be calculated from ckDataSize and block size */ char trackData[]; } ACD_DataTrackDataChunk; #endif /* ** Future CD alike media (e.g. DVD) might contain too much blocks to count the ** number of bytes in ckDataSize. This document does not try to solve this ** problem, because the audio data storable in AIFF itself is already limited ** the same way. */ /* ** Appendix I: example AIFF-CD file ** ** This hex dump describes an audio CD with ** a medium catalog number ("9876543219876") and ** two tracks: ** 1. audio data without preamphasize, ** starting at CD block #32, length 10 seconds, ** no ISRC, indices relativ to track start: ** #1: 0 seconds (by definition of a track) ** #2: 2 seconds ** #3: 5 seconds ** no index pause ** 2. audio data with preamphasize, ** starting at CD block #782, length 10 seconds, ** ISRC "UK POH 98 12345", indices: ** #1: 0 seconds (s.o.) ** index pause: 8 seconds ** ** AIFF form chunk: ** 464F524D 0035D5F4 41494646 ** "FORM" length "AIFF" ** common chunk: ** 434F4D4D 00000012 ** "COMM" length ** 0002 - 2 channels ** 000D7550 - 882000 sample frames = 20 seconds ** 0010 - 16 bit sampling size ** 400EAC44 00000000 0000 - frequency (see AIFF standard) ** track infos chunk: ** 54524946 0000004C ** "TRIF" length ** 00000001 - version 1 of AIFF-CD ** 00000001 - number of first track on CD ** 00000002 - two track in the file ** track infos for track #1: ** 00000020 - prepend pause of 32 blocks ** 00000000 - start at sample frame #0 in SSND chunk ** 0006BAA8 - 441000 sample frames long = 10 seconds ** 00000002 - flags: ACD_TRI_COPYRIGHTED ** 00000002 - two indices in addition to the obligatory one at the beginning ** 00000000 - number of reserved bytes: none ** 00000096 - indices at track block #150 = 2 seconds ** 00000177 - and at track block #375 = 5 seconds ** - _no_ index pause (ACD_TRI_PAUSE not set) ** 0000 - empty filename (length 0 + pad byte) ** no reserved bytes, track infos for track #2: ** 00000000 - no pause ** 0006BAA8 - start at sample frame #441000 = 10 seconds ** 0006BAA8 - 441000 sample frames long = 10 seconds ** 0000000B - flags: ACD_TRI_PREAMPHASIZE, ACD_TRI_COPYRIGHTED, ACD_TRI_PAUSE ** 00000001 - one index marker ** 00000000 - number of reserved bytes: none ** 00000258 - index _pause_ (ACD_TRI_PAUSE is set) at #600 = 8 seconds ** 0000 - empty filename ** medium catalog number chunk: ** 4D434E55 0000000E 39383736353433323139383736 00 ** "MCNU" length "9876543219876" pad byte ** ISRC chunk: ** 49535243 00000014 ** "ISRC" length ** 00000001 - one ISRC: ** 00000001 - track _index_ in infos array, i.e. ISRC is for track #2 ** 554B 4F484C 3938 3132333435 ** "UK OHL 98 12345" ** sound chunk: ** 53534E44 0035D548 ** "SSND" length ** [3528008 bytes of audio data follow] */ #endif /* AIFF_CD_H */